Kallikrein, trypsin-like proteases and amylase in mammalian submaxillary glands.

1. The tissue concentration of kallikrein, trypsin-like proteases and amylase has been determined in the submaxillary glands of the cat, dog, rabbit, rat, hamster and guinea-pig.2. Submaxillary gland extracts of the six species showed a wide variation in kallikrein content. The esterase activity in the extracts, however, did not correlate with the kininogenase activity of kallikrein. Both activities in each of the six species were affected by proteinase inhibitors but not in the same way.3. Evidence is presented which indicates that trypsin-like proteases similar to those described in the rat, also occur in the hamster and cat submaxillary glands.4. An even greater spread of amylase activity was observed between the species.5. The assumption that mammalian submaxillary kallikreins are identical proteins is questioned.